Comma Johanneum
From Textus Receptus
The Comma Johanneum is a comma (a short clause) contained in most translations of the First Epistle of John published from 1522 until the latter part of the nineteenth century, owing to the widespread use of the third edition of the Textus Receptus (TR) as the sole source for translation. In translations containing the clause, such as the King James Version, 1 John 5:7-8 reads as follows (with the Comma in bold print):
5:7 "For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one. 5:8 And there are three that bear witness in earth, the Spirit, and the water, and the blood: and these three agree in one."
The resulting passage is an explicit reference to the Trinity of Father, Son and Holy Spirit.